1. Field of the Invention
The present invention relates to a method of making a thin-film magnetic head using a magnetoresistive device, a method of making a magnetoresistive device assembly, a method of making a head gimbal assembly, and a method of making a hard disk apparatus.
2. Related Background Art
Recently, as hard disk apparatus have been improving their surface recording density, thin-film magnetic heads playing an important role in recording/reproducing magnetic information have also been required to improve their performances. As a thin-film magnetic head, a composite thin-film magnetic head in which a reproducing head having a magnetoresistive device (MR device) and a recording head having an inductive magnetic converting device are stacked on each other has recently become mainstream in place of one carrying out both recording and reproducing by an inductive magnetic converting device. Known as MR devices are AMR (Anisotropic MagnetoResistive) devices utilizing an anisotropic magnetoresistive effect, GMR (Giant MagnetoResitive) devices utilizing a giant magnetoresistive effect, TMR (Tunnel-type MagnetoResistive) devices utilizing a magnetoresistive effect generated in a tunnel junction, and the like.
An example of demands for a reproducing head is to narrow the track width of its MR film in order to improve reading performances. Narrowing the track width of MR film makes it possible to reduce magnetic information of a hard disk having a high surface recording density. For responding to such a demand, micromachining must be realized with a high precision. Therefore, attempts have been made to utilize electron beam lithography capable of writing at a precision higher than that of photolithography which has often been used in the making of thin-film magnetic heads. The electron beam lithography uses an electron beam having a wavelength shorter than light, thereby being able to form very fine patterns.